Changelog for #2162

Bugfix for imagetilesource _freeupCanvasMemory

changelog.txt

@@ -21,6 +21,7 @@ OPENSEADRAGON CHANGELOG
 * Fixed error caused by attaching MouseTracker to the page's document element (#2145 @tdiprima)
 * Added fallback and deprecation warning for Viewer.buttons (which got changed to buttonGroup in 3.0.0) (#2153 @devbyjonah)
 * Pinch to zoom now zooms around the center of the pinch, rather than the center of the viewer (#2158 @cavenel)
+* Fixed an issue that would sometimes cause problems with freeing up ImageTileSource memory (#2162 @pearcetm)
 
 3.0.0:
 

src/imagetilesource.js

@@ -272,8 +272,10 @@
          */
         _freeupCanvasMemory: function () {
             for (var i = 0; i < this.levels.length; i++) {
-                this.levels[i].context2D.canvas.height = 0;
-                this.levels[i].context2D.canvas.width = 0;
+                if(this.levels[i].context2D){
+                    this.levels[i].context2D.canvas.height = 0;
+                    this.levels[i].context2D.canvas.width = 0;
+                }
             }
         },
     });